Share your experience!
SONY XPERIA SP - ANDROID 4.3 UPDATE FIX (12.1.A.1.192)
http://www.ptcrb.com/vendor/complete/view_complete_request_guest.cfm?modelid=23022
WHEN IS IT COMMING?
WHAT CHANGES ARE WE EXPECTING?
Sunny
Solved! Go to Solution.
Latest available software
Android version: Google Android 4.3 (Jelly Bean)
Latest available software: 12.1.A.1.201
Release started: 2014-04-02

That may not be a bug fix - It may be a regional release as some countries have different versions of firmware
Your best contacting Sony and asking if it's a world wide release or regional http://www.sonymobile.com/global-en/support/contact-us/
sony... contact the team of XDA.... they can work for you
hehe they release a good firmware 
I have downgraded to 4.1.2... Got my phone back! The speed!! Fantastic phone :-))))
Until the kitkat arrives, I will change nothing! And I highly recommend, do the same. The 4.3 brings much mor trouble, than benefits!
4.1.2 ftw 
Hello guys!
Im suffering with the same problems of 4.3 too.. But i've just got my phone for 2013 Chritmas, and i still have warranty on it. Although im really disappointed in the phone with that 4.3. Do you think should i void my warranty just to get back to 4.1.2? 😕
Im afraid if something wrong happens with my phone, there will be no service who could fix a non-warranty mobile.
nothing cant go wrong... you will loose warranty if you unlock your bootloader.. you can flash stock 4.1.2 safe..